Mixer



Feb. 10, 1953 T, J, LAIRD 2,628,081

I MIXER Filed NOV- 12, 1948 ZSHEETSSHEET l INVENTOR. Thomas J Laird Feb. 10, 1953 T. J. LAlRD 2,628,081

MIXER Filed Nov. 12, 1948 2 SHEETS-SHEET 2 7770/770/5 J Lo/rd BY Patented Feb. 10, 1953 UNITED STATES P TENT o s J'- h rd X as is t T- J- Appli9fii2 sho es- P9; 12, 19-48, hath! rash 3 o ms- 1 This in e t o elates to a pa atus 9? mixin sain e am l a anal ghhsh h The o em of oroughl El m1 di p rsm pigments in v h cl and F $11? u j re of a t and e amel 9h? whi h has e n t e s b e t of ve y many ex e iments an a vas amount of research an 13 920 1 dev ses 9 heco hh h g ene: 4 :1 PPFP W PhVQJY' 5 r s f c ncy d SfififiactlQn ha e n o h rob em s a ce a es by he a that h seh s el' we o Pi m nts a pl gmenting materials are used-in an initial semisolid state and are very tenacious and difficult to break up and blend With theliduid vehicles and solvents, particularly since a yerycorriplete dispersion of the pigmentirie material-in the vehide or carrier is required; W

Also, the percentage composition of the semi solid pigmenting material is relatively-high in the ultimate paint mixture as 'eompa-refwith'varb ous other mixing processes in the industrial and chemical arts generally. Often the vehicles themselves, such as various drying oils and varn-ishes, are themselves quite yisoous which further contributes to the difficulty of attaining a thorough mixingahd 'dispersionwithin pra'tical and economic limitations.

'lh'e present apparatus is found by actual demonstration to thoroughly and disperse paint compositions, which include principally semi solid pigmenti-ng material and liquidvehicles or carriers, in a surprisingly thorough manner and in a period of time only'a fraction of fthat genorally required in mixers of thep'riOr art operating under generally similar conditions upon similar paint compositions.

The apparatus of the present invention has various features of novelty which are brought toether to produce, in combination, the desired end result of thorough rmixin g d dspersiop of the paint ingredients in a of time. However, one of the important ieatur s in and of itself is the relationship of them-am agitator or rotor "of the mixer and a slotted stator which shrouds it intimately in such manner -that r'natei ialls mixed at the point of cooperatioii of two elements with what appears to be a shearing migring action which produces full and complete dispersion of the pigmenting materials the yehicles in a time heretoforfnnattainahle under other generally similar conditions;

A complete and specific embodiment of the in vention is illustrated in the afiompanyin g draw lugs and described ll the ,fqllpwing (o1. ass- 9 1 i2 that this embodiment ise hihhth *QYVWQY o B ample only, and the h I ve tion isnotlimi-ted except n a 8. 1?! h h hims- J Ii hhfiil l I l 5 F i is a ert c l h hssse ii h l vi w 9 htrally through a'mixin'g vessel embodying one orm or the. pr sen hi ehtioh;

Fis- 7 a top hlhh' V ew thereo w th. h h Q e m9i?? 3 is a vertical jragmentary cross seotional View on a a er s al ta I ir u hth mf x n elements themselves; and F l is a fr gmen ism plan i of the stator element shown I t'ia'l'ly'f incross-se'etion for added illustration and with a "perti'onof the.

mixing rotor indicated? u ho he stem; gu s o t sirhwins'sr like characters of reierenoe'denote lik parts, and the numeral I'D do "s a g nr 1 v cylindrical round bottomed yessefw ch is provided with a detachably secured 'poyi" Element 1 of any conventional tor-in; The lower-portion of vessel [0 is surrounded by a water jacket" I 2' in which coolto alosorb'a' considby the rather s. PP..F@?1 .S :BQi i flanged plate 14 i eeme ten e when of ng Pa t ularl t F Wh s h sup rts th im in a. cen ra on nin I a. c s e of ves l I in ny d sir or. hi" of the ltehdhu c hhehhiens hidl htd a in r 1 and} r A ari gsleeve. l isshchre tra lyof plat M by weldingor the ire'aiid $.d0WnWardly therefrom- At the uppe 'p r on of slee e H there is a circular nut element 18 which, screws int plate s shh'wh in ig- Ban 'hrovi s an exte nally t reasied retain n ring thr into the-low f dot I e esth hh er ac 9 h 5o Tlhe. fo fi i being ,c 15 a ti n provides sealedhearing ifora'mixers .is ly r at d m 7 l hyan edesi h e mot v throushai ,grhtori f.

mediately above plate M, as by means of a Woodrufi key and a set screw 26 in the hub of rotor 24. The blades of roller 24 are curved as viewed in plan, see Fig. 2, so as to present slightly trailing outer edge portions, as indicated fragmentarily in Fig. 4. The rotation of rotor 24 will be clockwise as viewed in Fig. 2. A stator element 28 which is illustrated in Figs. 3 and 4 comprises an annular disc having a concave recess formed in its under surface to receive rotor 24. The contours of the recess in stator element 28 and rotor 24 are complementary, as appears from Fig. 3.

Radially beyond rotor 24 stator element 23 has an annular ring portion 3| provided with a series of outwardly extending slots 32. The outer ends of the blades of rotor 24 are arcuate and concentric with the inner periphery of ring portion 3| of the stator element as shown in Fig. 4 and rub intimately against the inner periphery of ring portion 3| and thus force material through slots 32 by a combined centrifugal, squeezing and shearing action which appears .to produce a much quicker and more efiicient distribution and dispersion of paint materials than as heretofore been obtainable. v

The slots 32 in the form shown in the present embodiment are not radial but slant in a clockwise direction from the inner periphery to the outer periphery of ring portion 3|. As shown in detail in Fig. 1, the arcuate outer ends of the impeller blades have a considerable area or engagement with the inner periphery of ring portion 3! of the shroud element 28 whereby the impeller exerts a broad squeezing and shearing action against such inner periphery.

Referring to Fig. 3, an annular chamber 35 of generally triangular cross-section is provided at the upper side of shroud element 23 and may be formed by welding or brazing an inverted V ring 38 to the top of shroud element 28. This provides a cooling chamber in intimate association with the mixing device itself and also provides an entry throat to the mixing rotor from above. In Fig. 3 it will be noted that one of the screws 3?. which holds shroud element 28 to plate id has an opening thereto and an inlet passage 39 leads from. the upper end of the screw into chamber 35. A similar diametrically opposite screw and passage is indicated at 40 in Fig. 4 which provides an outlet passage and a conduit in chamber 35 leads from the upper' end of the outlet passage, at the upper surface of shroud 28, to the upper part of chamber 35.

Cooling water is introduced through opening 38 by means of a conduit 42 leading therefrom as shown in Fig. l and water discharged-from conduit 4i and outlet passage screw passes from the mixer as by means of a conduit 43. It will be seen from the foregoing that cooling water is intrcluced from the bottom of chamber 35 and taken oii at the top where the water temperature would naturally be greatest. The inlet conduit 52 may be connected with any water supply under pressure such as an ordinary city water supply.

The upper endof mixing shaft 23 is provided with an impeller 45 which rotates with rotor 25 and tends to preliminarily break up the pigment and force it downwardly toward the throat disposed concentrically within cooling chamber 35.

A series of bailie plates are provided along the interior walls of vessel "land, as shown clearly in Figs. '1 and v2, eachfbaffle comprises a pair of plates Strand 5! which extend generally'parallel to the inner wall of vessel Hi, plate 58 being spaced inwardly from the wall and plate 5| being spaced somewhat inwardly from plate 50. Each pair of plate elements and 5| is fixed to a pair of mounting pins 52 and 53 which are welded or otherwise fixed to the interior wall of vessel Iii. One plate 50 is fixed to one side of a pair of rods 52 and 53 as by welding or the like, and the other plate 51 is fixed to the opposite sides of rods 52 and 53 so that the baffle plates of each pair are ofiset in a direction circumferentially of the vessel by a distance equal substantially to the diameters of pins 52 and 53.

What is claimed is:

1. Dispersion apparatus comprising a vessel and dispersion means therein comprising a stator and a rotor disposed therein, said stator comprising upper and lower discoidal portions lying closely adjacent the upper and lower surfaces of the rotor and including a central opening for ingress of material to be dispersed, said stator having an annular portion extending between the upper and lower discoidal portions and about the rotor, said rotor having outwardly projecting blades proportioned to terminate in relatively close juxtaposition to the inner periphery of the annular portion of the stator, said annular portion having a circumferential series of outwardly extending passages of relatively narrow crosssection as compared with their outward extent, and an axial displacement impeller disposed outside of said central opening and fixed for rotation with the rotor for urging material toward said central opening.

2. Dispersion apparatus comprising a vessel and dispersion means therein comprising a stator and a rotor disposed therein, said stator comprising upper and lower discoidal portions lying closely adjacent the upper and lower surfaces of the rotor and including a central opening for ingress .of material to be dispersed, said stator having an annular portion extending between the upper and lower discoidal portions and about the rotor, said rotor having outwardly projecting blades disposed-to trail relative to the direction of rotation and proportioned to terminatein rela tively close juxtaposition to the inner periphery of the annular portion of the stator, said annular portion having a circumferential series of outwardly extending vertical slots of relatively narrow width as compared with their outward extent, and an annular liquid heat exchange casing disposed against one of said discoidal portions to cool the rotor and the annular portion of the stator and form an intake throat to the rotor.

THOMAS J. LAIRD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 423,285 Smith et a1. Mai. 11, 1890 1,701,164 Shafor Feb. 5, 1929 1,742,226 Thurm et al Jan. 7, 1930 1,794,214 Thurm et al Feb. 24, 1931 2,176,220 v Marshall et a1. Oct. 17, 1939 2,212,261 Brothman Aug. 20, 1940 2,390,898 Rechtin et al. Dec. 11, 1945 FOREIGN PATENTS Number Country. Date 419,976 Great Britain Nov. 22, 193.4 "630,754 Germany June 5, 1936 

